[xg15]

Sorry, you're right of course (and yeah, the Pacific rim can obviously not be in the Atlantic, typed too fast there...)

With "opposite" I meant the role in plate tectonics, in that classical volcanoes seem to mostly appear near subduction zones or hotspot but not on the ridges from what I know. (Iceland being the exception, but even there it's because of a hotspot that happens to be located right on the ridge)

But I think the ridge system usually does not have volcanoes in the sense that there are magma chambers that fill up or cause eruptions. So the usual scenario of the "asleep supervolcano" does not apply.

> The supervolcano complex under the Pacific is one of the largest known in the solar system, however.

That sounds interesting. Do you have some links about that?

[MrDrMcCoy]

My recollection seems to have been from a very early story on the subject and got some terminology wrong. Apparently, supervolcanoes have to have had an eruption in the past of a certain magnitude in order to earn that title, and that hasn't happened yet. Pretty sure it was this: https://en.wikipedia.org/wiki/Tamu_Massif